1. Field of the Invention
This invention relates to a flatbed scanner, and more particularly, to a flatbed scanner that uses a single dynamic source to support dynamic for both the light projection device and the image pick-up device of the flatbed scanner.
2. Description of the Prior Art
Nowadays, kinds of scanners are broadly used in computers. Some scanners can scan reflective documents by feeding the reflective documents into the scanners themselves, however, transparent documents only can be scanned through the assistant devices of the scanners. A convenient way for scanning both of the transparent and reflective documents is to apply flatbed scanners. Accordingly, after the transparent documents are put at the top of the transparent windows of the flatbed scanners, the transparent documents can thus be scanned through the cooperation of both the light source and the image generation devices.
FIG. 2 depicts the cross section of a conventional flatbed scanner 20 that is composed of an upper portion 201 and a lower portion 202 for cooperatively scanning a scanned document 218. The upper portion 201 and a lower portion 202 are fastened by using a connection apparatus 219, and the scanned document 218 can be a transparent document such as a projection slide or a lantern slide. When scan operations start, the dynamic generated by the motor 208 of the upper portion 201 will be transferred through gear sets 207, a pulley 203, and a transmission belt 204 to drive the light projection device 205. In addition, a dynamic generated by the motor 216 of the lower portion 202 is transferred through gear sets 215, a pulley 209, and transmission belt 210 to drive the image pick-up device 211. The light projection device 205 further includes a light source 206. Furthermore, the image pick-up device 211 encompasses a scanning set, which further comprises a light source 212, mirrors 217, lenses 213, and a CCD (Charge-Coupled Device) sensor 214. As noted, both the light projection device 205 and the image pick-up device 211 move together to scan the scanned document 218 cooperatively. Moreover, the light source 206 is used for scanning the transparent documents, and the light source 212 is used to scan the reflective documents.
Evidently, in the flatbed scanner, both of the upper and lower portions respectively need a motor to generated required dynamic. It is obvious that more power consumption and further components are necessary to establish the flatbed scanner 20, and more controlled lines are also required for controlling the cooperation between the light projection device 205 and the image pick-up device 211. A need has been arisen to disclose a flatbed scanner, in which less power consumption and fewer required components are needed for controlling the scan operations.